huginn: Email Digest Agent error 'Exception during check. end of file reached:'

System Ubuntu 18.04, do not use docker, just have done all things mentioned in https://github.com/cantino/huginn/tree/master/doc/manual when using Email Digest Agent got error information.

the related settings: SMTP_DOMAIN=126.com SMTP_USER_NAME=xxxxxx@126.com SMTP_PASSWORD=secret SMTP_SERVER=smtp.126.com SMTP_PORT=587 SMTP_AUTHENTICATION=plain SMTP_ENABLE_STARTTLS_AUTO=true SEND_EMAIL_IN_DEVELOPMENT=true

I also enable the special email setting for SMTP service and set a special key for POP3/IMAP/SMTP/Exchange/CardDAV/CalDAV service.

got the following error information: Exception during check. end of file reached: /usr/local/lib/ruby/2.6.0/net/protocol.rb:225:in rbuf_fill' /usr/local/lib/ruby/2.6.0/net/protocol.rb:225:in rbuf_fill’ /usr/local/lib/ruby/2.6.0/net/protocol.rb:191:in readuntil' /usr/local/lib/ruby/2.6.0/net/protocol.rb:201:in readline’ /usr/local/lib/ruby/2.6.0/net/smtp.rb:950:in recv_response' /usr/local/lib/ruby/2.6.0/net/smtp.rb:553:in block in do_start’ /usr/local/lib/ruby/2.6.0/net/smtp.rb:960:in critical' /usr/local/lib/ruby/2.6.0/net/smtp.rb:553:in do_start’ /usr/local/lib/ruby/2.6.0/net/smtp.rb:518:in start' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/mail-2.7.1/lib/mail/network/delivery_methods/smtp.rb:109:in start_smtp_session’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/mail-2.7.1/lib/mail/network/delivery_methods/smtp.rb💯in deliver!' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/mail-2.7.1/lib/mail/message.rb:2159:in do_delivery’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/mail-2.7.1/lib/mail/message.rb:260:in block in deliver' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/actionmailer-5.2.2.1/lib/action_mailer/base.rb:560:in block in deliver_mail’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in block in instrument' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications/instrumenter.rb:23:in instrument’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in instrument' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/actionmailer-5.2.2.1/lib/action_mailer/base.rb:558:in deliver_mail’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/mail-2.7.1/lib/mail/message.rb:260:in deliver' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/actionmailer-5.2.2.1/lib/action_mailer/message_delivery.rb:114:in block in deliver_now’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/actionmailer-5.2.2.1/lib/action_mailer/rescuable.rb:17:in handle_exceptions' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/actionmailer-5.2.2.1/lib/action_mailer/message_delivery.rb:113:in deliver_now’ /home/huginn/huginn/app/models/agents/email_digest_agent.rb:61:in block in check' /home/huginn/huginn/app/models/agents/email_digest_agent.rb:52:in each’ /home/huginn/huginn/app/models/agents/email_digest_agent.rb:52:in check' /home/huginn/huginn/app/jobs/agent_check_job.rb:7:in perform’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/execution.rb:39:in block in perform_now' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:109:in block in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/i18n-1.6.0/lib/i18n.rb:297:in with_locale' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/translation.rb:9:in block (2 levels) in module:Translation’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in instance_exec' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in block in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/logging.rb:26:in block (4 levels) in <module:Logging>' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in block in instrument’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications/instrumenter.rb:23:in instrument' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/notifications.rb:168:in instrument’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/logging.rb:25:in block (3 levels) in <module:Logging>' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/logging.rb:46:in block in tag_logger’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/tagged_logging.rb:71:in block in tagged' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/tagged_logging.rb:28:in tagged’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/tagged_logging.rb:71:in tagged' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/logging.rb:46:in tag_logger’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/logging.rb:22:in block (2 levels) in <module:Logging>' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in instance_exec’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in block in run_callbacks' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:136:in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/execution.rb:38:in perform_now' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/execution.rb:24:in block in execute’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:109:in block in run_callbacks' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/railtie.rb:28:in block (4 levels) in class:Railtie’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/execution_wrapper.rb:87:in wrap' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/reloader.rb:73:in block in wrap’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/execution_wrapper.rb:87:in wrap' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/reloader.rb:72:in wrap’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/railtie.rb:27:in block (3 levels) in <class:Railtie>' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in instance_exec’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:118:in block in run_callbacks' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.2.1/lib/active_support/callbacks.rb:136:in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/execution.rb:22:in execute' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/activejob-5.2.2.1/lib/active_job/queue_adapters/delayed_job_adapter.rb:42:in perform’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/backend/base.rb:81:in block in invoke_job' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:61:in block in initialize’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:66:in execute' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:40:in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/backend/base.rb:78:in invoke_job' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:230:in block (2 levels) in run’ /usr/local/lib/ruby/2.6.0/timeout.rb:93:in block in timeout' /usr/local/lib/ruby/2.6.0/timeout.rb:103:in timeout’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:230:in block in run' /usr/local/lib/ruby/2.6.0/benchmark.rb:308:in realtime’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:229:in run' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:312:in block in reserve_and_run_one_job’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:61:in block in initialize' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:66:in execute’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:40:in run_callbacks' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:312:in reserve_and_run_one_job’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:213:in block in work_off' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:212:in times’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:212:in work_off' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:175:in block (4 levels) in start’ /usr/local/lib/ruby/2.6.0/benchmark.rb:308:in realtime' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:174:in block (3 levels) in start’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:61:in block in initialize' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:66:in execute’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:40:in run_callbacks' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:173:in block (2 levels) in start’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:172:in loop' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:172:in block in start’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/plugins/clear_locks.rb:7:in block (2 levels) in <class:ClearLocks>' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:79:in block (2 levels) in add’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:61:in block in initialize' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:79:in block in add’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:66:in execute' /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/lifecycle.rb:40:in run_callbacks’ /home/huginn/huginn/vendor/bundle/ruby/2.6.0/gems/delayed_job-4.1.5/lib/delayed/worker.rb:171:in start' /home/huginn/huginn/lib/delayed_job_worker.rb:6:in run’ /home/huginn/huginn/app/concerns/long_runnable.rb:71:in `block in run!’